Self-modifying Brainfuck, 39 bytes

< - [ . <<- ] " e m s p X ! - p m m f I

Try it online!

###Explanation### For anyone that is not familir with self-modifying brainfuck: The program itself gets put into registers directly left to where you start out from. This allows for some cool stuff you can't do with regular brainfuck.

This program will move back two registers (one with every second char removed) increment it and output in until the loop stops. The loop will stop once you increment the char that ends the loop itself thus making brainfuck ignore it.

Version without every second character:

 <-[.<-]"emspX!-pmmfI     

Self-modifying Brainfuck, 39 bytes

< - [ . <<- ] " e m s p X ! - p m m f I

Try it online!

Explanation

For anyone that is not familir with self-modifying brainfuck: The program itself gets put into registers directly left to where you start out from. This allows for some cool stuff you can't do with regular brainfuck.

This program will move back two registers (one with every second char removed) increment it and output in until the loop stops. The loop will stop once you increment the char that ends the loop itself thus making brainfuck ignore it.

Version without every second character:

 <-[.<-]"emspX!-pmmfI